QuickFix: Move helpers from QuickFixData to RefactoringFile.

Makes them easy to use everywhere. Also when calling
QuickFixData::textOf and friends, it wasn't really clear which file
they would run on.

src/plugins/cppeditor/cpprefactoringchanges.h

@@ -48,6 +48,7 @@ class CPPEDITOR_EXPORT CppRefactoringFile: public TextEditor::RefactoringFile
 public:
     CppRefactoringFile();
     CppRefactoringFile(const QString &fileName, CppRefactoringChanges *refactoringChanges);
+    CppRefactoringFile(TextEditor::BaseTextEditor *editor, CPlusPlus::Document::Ptr document);
 
     CPlusPlus::Document::Ptr cppDocument() const;